JP2006521916A - Catalyst for gas phase partial oxidation reaction and method for producing the same - Google Patents

Abstract

The present invention relates to a catalyst for partial oxidation reaction and a method for producing the same, and by using a drying control additive at the time of catalyst production, shows high activity in conversion of propylene or isobutylene in the partial oxidation reaction, such as acrolein and methacrolein. The present invention relates to a method for producing a composite metal oxide catalyst capable of maintaining a high selectivity for an unsaturated aldehyde and producing an unsaturated carboxylic acid such as acrylic acid or methacrylic acid in a high yield by stable factory operation.

Description

  The present invention relates to a catalyst for partial oxidation reaction and a method for producing the same, and more particularly, a composite used in a process for producing an unsaturated aldehyde such as acrolein or methacrolein by reacting air or oxygen-containing gas with propylene or isobutylene. The present invention relates to a metal oxide catalyst and a method for producing the same.

  Acrylic acid is a basic raw material for various acrylates widely used in highly hygroscopic resins and paints, adhesives, brighteners, electrical insulation materials, leather processing, textile processing, paper processing, etc., and development of polymerization processing technology At the same time, the demand continues to increase.

  The acrylic acid or methacrylic acid is produced by industrially partially oxidizing propylene or isobutylene and then oxidizing the product acrolein or methacrolein.

  That is, the method for producing acrylic acid or methacrylic acid by the partial oxidation of propylene or isobutylene comprises a two-stage reaction. The first reaction is a reaction in which propylene or isobutylene is oxidized to acrolein or methacrolein using an oxide catalyst having molybdenum and bismuth as core components, and the second reaction is acrolein using molybdenum and a vanadium-based oxide catalyst. Alternatively, it is a reaction in which methacrolein is oxidized again to acrylic acid or methacrylic acid.

  When producing the acrylic acid or methacrylic acid, the better the catalyst performance, the higher the selectivity. Therefore, research to improve the performance of the catalyst using Mo-Bi as a basic component has been actively promoted. .

  As such prior art, US Pat. No. 2,941,007 (J.L. Callahan et al.) Disclosed a catalyst comprising bismuth molybdate or bismuth phosphomolybdate. U.S. Pat. No. 3,171,859 (K. Sennewald et al.) Disclosed a catalyst composed of Fe, Bi, P, Mo and O. U.S. Pat. No. 3,522,299 (S. Takenaka et al.) Disclosed a catalyst composed of Ni, Co, Fe, Bi, Mo, P, As and O. U.S. Pat. No. 3,089,909 (JLBarclay et al.) Discloses a catalyst selected from the group consisting of tin tungstate, silver tungstate and bismuth tungstate. , 825,600 (T. Ohara et al.) Discloses a catalyst composed of Mo, Co, Fe, Bi, W, Si, alkali metal, and the like. In addition, Korea Patent Publication No. 2003-18917, Korea Patent Publication No. 2002-43801, US Patent No. 4,873,217, US Patent No. 4,224,187 etc. improve the performance of the catalyst through various manufacturing methods. A method of enhancing is disclosed. In US Pat. No. 4,248,803 and US Pat. No. 5,017,542, the catalyst components and composition ratios are adjusted to increase the conversion rate of propylene and the yield of acrolein and acrylic acid. And a method for manufacturing the same. However, when producing a suspension of a catalyst that partially oxidizes propylene or isobutylene to acrolein or methacrolein, the above-described method is used to stir the precipitate formed by the reaction between the cationic metal salt and the anionic metal salt present in the aqueous solution. It is difficult to maintain a uniform suspension because it settles at a high speed and phase separation occurs with the aqueous layer.

  In order to solve such problems, Korean Patent Publication No. 2002-27023 disclosed a method using a variety of acids to produce a uniform solution without metal precipitation during suspension production. . However, although the above method is also easy to produce a uniform suspension, there is a problem that the physical property value and performance of the catalyst may be deteriorated because the acid added in the calcination step is rapidly decomposed.

  In other words, the existing method for producing a composite metal oxide catalyst attempts to achieve layer separation suppression and particle size reduction in the precursor suspension by using an organic acid when the precursor suspension is produced. However, when a suspension is produced using an organic acid, the problems of layer separation and particle size can be solved, but the organic acid is rapidly decomposed during the drying and firing processes, and the developed pores become uniform. A phenomenon occurs in which the surface area and physical properties of the catalyst decrease due to partial damage.

As described above, various researches have been conducted on the production method of acrylic acid and methacrylic acid to increase the yield by using a conventional molybdenum-bismuth-cobalt-iron oxide compound catalyst and various composite oxide catalysts. I came. However, in order to obtain a catalyst exhibiting higher activity and selectivity, development for existing oxide catalyst manufacturing methods such as molybdenum-bismuth-cobalt-iron-potassium is continuously required.
US Pat. No. 2,941,007 (JLCallahan et al.) US Pat. No. 3,171,859 (K. Sennewald et al.) US Pat. No. 3,522,299 (S. Takenaka et al.) US Pat. No. 3,089,909 (JLBarclay et al.) US Pat. No. 3,825,600 (T.Ohara et al.) Korean Patent Publication No. 2003-18917 Korean Patent Publication No. 2002-43801 US Pat. No. 4,873,217 U.S. Pat. No. 4,224,187 U.S. Pat. No. 4,248,803 US Pat. No. 5,017,542 Korean Patent Publication No. 2002-27023

  Therefore, the object of the present invention to solve the problems of the prior art is to prevent the rapid decomposition of the acid added during catalyst production and maintain a high selectivity for acrolein and methacrolein, thereby converting propylene and isobutylene. It is an object of the present invention to provide a catalyst for partial oxidation reaction of propylene or isobutylene, which can improve the yield of acrylic acid and methacrylic acid as final products through stable factory operation, and a method for producing the same.

  Another object of the present invention is to provide a method for producing acrylic acid or methacrylic acid, which is an unsaturated carboxylic acid, using the catalyst for partial oxidation reaction of propylene or isobutylene.

  Another object of the present invention is to provide a method for producing an unsaturated nitrile using the catalyst for partial oxidation reaction of propylene or isobutylene.

  The present invention maintains high selectivity for unsaturated aldehydes such as acrolein or methacrolein, unsaturated carboxylic acids such as acrylic acid or methacrylic acid, and unsaturated nitriles by utilizing a drying control additive during catalyst manufacture. Thus, it is possible to provide a catalyst with high yield and excellent reproducibility through stable factory operation.

In order to achieve the above object, the present invention provides a catalyst for partial oxidation reaction represented by the following chemical formula 1 having a surface area of 15 to 18 m ² / g.
[Chemical formula 1]
_{Mo a Bi b Fe c X d} Y e O f
(Wherein, X is one or more elements selected from the group consisting of Co and Ni; Y is one or more elements selected from the group consisting of K, Cs and Rb; a, b , C, d, e and f represent the atomic ratio of each element; provided that when a is 12, b is 0.5-2, c is 0.5-2, d is 3-8, e is 0.005 to 0.2, and f is a numerical value depending on the oxidation state of each element)

  In addition, the present invention provides (a) an aqueous solution of a metal salt selected from the group consisting of molybdenum, bismuth, iron, cobalt, nickel, potassium, cesium and rubidium in an organic acid, and then a drying control additive. Adding a catalyst to produce a catalyst suspension; (b) vacuum drying and grinding the catalyst suspension to produce a catalyst powder; and (c) firing the catalyst powder in an air atmosphere. And a method for producing a catalyst for partial oxidation reaction of Formula 1. At this time, the catalyst of Formula 1 is most preferably used as a catalyst for partial oxidation reaction of propylene or isobutylene.

  The present invention also provides a method for producing an unsaturated carboxylic acid comprising a step of partially oxidizing an alkane, alkene or mixture thereof in the presence of the composite metal oxide catalyst produced by the above method.

  The present invention also provides a method for producing an unsaturated nitrile comprising the step of partial oxidation reaction of ammonia with alkane, alkene or a mixture thereof in the presence of the composite metal oxide catalyst produced by the above method.

  The present invention will be described in detail below.

  In order to prevent rapid degradation of organic acids when producing suspensions using organic acids, the present inventors have added a drying control additive as a substance that can control rapid degradation of organic acids. By gradually maintaining the acid decomposition rate, it was confirmed that pore growth and physical properties of the catalyst were improved, and the present invention was completed.

  The present invention is characterized by providing a method for producing a catalyst that maintains high selectivity for acrolein and methacrolein, exhibits high activity in the conversion of propylene and isobutylene, and enables stable factory operation.

In particular, the active component of the composite metal oxide catalyst of the present invention is represented by the chemical formula 1, and the final catalyst obtained by using the drying control additive has a surface area of 15 to 18 m ² / g to increase the catalytic activity. Can be increased. At this time, if the surface area is less than 15 m ² / g, there is a problem that the activity of the catalyst is lowered. If the surface area exceeds 18 m ² / g, the amount of the additive such as propionic acid is increased to increase the catalyst surface area. There is a problem that selectivity falls.

  Therefore, the catalyst of the present invention can be usefully used for producing an unsaturated carboxylic acid through a partial oxidation reaction in which an alkane, an alkene or a mixture thereof is reacted with oxygen. As a preferred example, in the present invention, an unsaturated aldehyde such as acrolein or methacrolein can be produced by reacting propylene or isobutylene with oxygen under the catalyst of Formula 1. Thereafter, acrylic acid or methacrylic acid can be obtained in a high yield by oxidizing the acrolein or methacrolein.

  The method for producing a composite metal oxide catalyst of Formula 1 which is a catalyst for partial oxidation reaction of the present invention will be described in more detail.

  First, in the present invention, each metal salt of a composite metal oxide is dissolved using water and an organic acid, and then a drying control additive is added to produce a catalyst suspension.

  Thereafter, the catalyst suspension is vacuum-dried to obtain a cake-form catalyst, which is pulverized to produce a powder-form catalyst.

  Finally, the catalyst in powder form is collected and fired in a firing furnace to manufacture the composite metal oxide catalyst of Formula 1. The firing conditions are not particularly limited, and can be performed, for example, in an air atmosphere. Preferably, baking is performed at a temperature of 400 to 450 ° C. for 5 to 10 hours.

  At this time, in the method for producing a composite metal oxide catalyst of Formula 1 according to the present invention, if an organic acid is used when producing a precursor liquid of the composite metal oxide catalyst, a chelate is obtained by a reaction between the organic acid and the metal oxide. Form a compound. Since the produced chelate compound is well dissolved in water, not only the precipitation of the metal that occurs during the production of the metal oxide catalyst by the precipitation method can be prevented, but also smaller catalyst particles can be produced. Another effect of adding the organic acid is to promote pore formation of the metal oxide catalyst while the organic acid is decomposed to increase the surface area of the catalyst, and the increased surface area increases the activity of the catalyst. However, the pores generated due to the rapid decomposition of the organic acid and water in the heat treatment process such as drying and baking process are partially damaged. Pore damage reduces catalyst performance and surface area.

  Therefore, the present invention adjusts the decomposition rate of water and organic acid by adding a substance having a lower surface tension than water and a higher boiling point than water to prevent rapid decomposition of organic acid and water as a drying control additive. There is a feature.

  Dry control additives used in the present invention include glycerol, propionic acid, formamide, nitromethane, propyl alcohol, butyl alcohol, ethanediol, nitroethane, amyl acetate, ethyl propionate, ethyl malonate, furfurol, (α, β, γ) -picoline, piperidine, phenylhydrazine, 1-pentanol, 3-methylbutanol, and isovaleric acid can be selected and used, preferably formamide, propionic acid, glycerol .

  The content of the drying control additive is preferably 10 to 60% by weight and more preferably 20 to 40% by weight per 100% by weight of the organic acid.

  The precursor liquid of the composite metal oxide catalyst of the present invention can be produced by mixing an amount of a metal salt suitable for forming the composite metal oxide catalyst and at least one solvent, which is a slurry, There may be a dispersion, a solution or a combination thereof. The slurry, dispersion, and solution are mixed so that the atomic ratio of each metal component is equivalent to the metal ratio in the composite metal oxide catalyst to be produced.

  The solvent used to produce the precursor liquid includes water, and the amount of water is substantially sufficient to minimize or avoid compositional separation and / or phase separation during production. It is preferred that the amount be sufficient to be maintained in solution. Thus, the amount of water can vary depending on the amount and solubility of the compounded material. At this time, if the amount of water is small, a slurry can be formed, but it is preferable that the amount of water is sufficient so that an aqueous solution can be easily formed during mixing.

  The metal component used in the production of the composite metal oxide catalyst of the present invention is selected in the form of metal ammonium salt, nitrate, oxide, carbonate, chloride, sulfate, hydroxide, and organic acid salt. However, it is not limited to these. At this time, as the metal component, at least one selected from the group consisting of molybdenum, bismuth, iron, cobalt, nickel, potassium, cesium and rubidium can be used.

  Moreover, it is preferable that the organic acid added at the time of catalyst suspension manufacture is a C1-C10 organic acid selected from 1 or more types from the group which consists of nitric acid, a citric acid, a maleic acid, and an oxalic acid. The content of the organic acid can be adjusted according to the total number of moles of the metal salt nitrate anion, and the content of the organic acid is used in a ratio of 0.5 to 10 moles per mole of the metal salt nitrate anion. Is preferred.

  When the catalyst produced by the above method is used commercially, it is formed into a certain size and shape by a usual method such as extrusion. In the present invention, the reaction conditions for producing the catalyst are not particularly limited, and the reaction can be carried out by a usual method.

  In addition, the present invention can produce an unsaturated carboxylic acid and an unsaturated nitrile using the catalyst of Formula 1 as a catalyst for partial oxidation reaction.

  The present invention provides a method for producing an unsaturated carboxylic acid, comprising the step of partially oxidizing an alkane, alkene or mixture thereof in the presence of the composite metal oxide catalyst produced by the above method.

  The present invention also provides a method for producing an unsaturated nitrile comprising a step of partially oxidizing an alkane, alkene or mixture thereof with ammonia in the presence of the composite metal oxide catalyst produced by the above method.

  The unsaturated carboxylic acid is preferably acrylic acid or methacrylic acid obtained through a partial oxidation reaction of propylene or isobutylene.

  For example, the catalyst can be usefully used for the production of acrolein and acrylic acid or the production of methacrolein and methacrylic acid by the vapor phase catalytic oxidation reaction of propylene in a fixed bed multi-tube reactor. Any reaction conditions can be introduced, and the reaction conditions are not particularly limited.

  The present invention will be described in more detail through the following examples and test examples. However, the following examples are merely illustrative of the present invention and do not limit the present invention.

Example: Catalyst production Example 1
400 ml of distilled water was placed in a 500 cc glass reactor and heated to 75 ° C. with stirring. After 100 g of citric acid was dissolved in this solution, 100 g of ammonium molybdate, 19.7 g of ferric nitrate, and 54.95 g of cobalt nitrate were sequentially added and completely dissolved. After the temperature of the solution was lowered to 50 ° C., a solution of 34.35 g of bismuth nitrate and 0.286 g of potassium nitrate dissolved in nitric acid was added, and finally 60 g of formamide was added to prepare a slurry solution. Then, it was dried under a 120 ° C. vacuum rotary dryer. The dried catalyst cake was collected and pulverized to 40 mesh size to produce catalyst powder. The catalyst powder was collected and calcined in a 450 ° C. firing furnace for 5 hours to produce a catalyst. Firing was performed in an air atmosphere. The catalyst composition was Mo ₁₂ Bi _1.5 Co _4.4 Fe ₂ K _0.06 .

Comparative Example 1
300 ml of distilled water was placed in a glass reactor and heated to 75 ° C. To this, 100 g of ammonium molybdate was dissolved, and a solution obtained by dissolving 19.7 g of iron nitrate, 60.44 g of cobalt nitrate, 34.35 g of bismuth nitrate, and 0.286 g of potassium nitrate in nitric acid was added to the solution in which the molybdenum salt was dissolved. Thus, a catalyst was produced. The cake dried by a vacuum dryer was recovered and pulverized to a size of 40 mesh to produce a catalyst powder, which was treated in a baking furnace at 450 ° C. for 5 hours. The catalyst composition was Mo ₁₂ Bi _1.5 Co _4.4 Fe ₂ K _0.06 .

Comparative Example 2
400 ml of distilled water was placed in a 500 cc glass reactor and heated to 75 ° C. with stirring. After 100 g of citric acid was dissolved, 100 g of ammonium molybdate, 39.4 g of ferric nitrate, and 60.44 g of cobalt nitrate were sequentially added and dissolved completely. The temperature of the solution was lowered to 50 ° C., and a solution of 34.35 g of bismuth nitrate and 0.286 g of potassium nitrate dissolved in nitric acid was added to prepare a slurry solution. Then, it was dried under a 120 ° C. vacuum rotary dryer. The dried catalyst cake was collected and pulverized to 40 mesh size to produce catalyst powder. The catalyst powder was collected and calcined in a 450 ° C. firing furnace for 5 hours to produce a catalyst. Firing was performed in an air atmosphere. The catalyst composition was Mo ₁₂ Bi _1.5 Co _4.4 Fe ₂ K _0.06 .

Example 2
400 ml of distilled water was placed in a 500 cc glass reactor and heated to 75 ° C. with stirring. After 100 g of citric acid was dissolved, 100 g of ammonium molybdate, 39.4 g of ferric nitrate, and 60.44 g of cobalt nitrate were sequentially added and completely dissolved. The solution was lowered to 50 ° C., a solution of 34.35 g of bismuth nitrate and 0.286 g of potassium nitrate dissolved in nitric acid was added, and 50 g of glycerol was added to prepare a slurry solution. The drying and firing processes were the same as in Example 1. The catalyst composition was Mo ₁₂ Bi _1.5 Co _4.4 Fe ₄ K _0.06 .

Example 3
400 ml of distilled water was placed in a 500 cc glass reactor and heated to 75 ° C. with stirring. After 100 g of citric acid was dissolved in this solution, 100 g of ammonium molybdate, 19.7 g of ferric nitrate, and 54.95 g of cobalt nitrate were sequentially added and completely dissolved. The solution was lowered to 50 ° C., a solution of 34.35 g of bismuth nitrate dissolved in nitric acid and 0.286 g of potassium nitrate was added, and finally 20 g of propionic acid was added to prepare a slurry solution. The drying and firing processes were the same as in Example 1. The catalyst composition was Mo ₁₂ Bi _1.5 Co _4.4 Fe ₂ K _0.06 .

Example 4
A catalyst was prepared in the same manner as in Example 3 except that 40 g of propionic acid was used.

Example 5
A catalyst was prepared in the same manner as in Example 3 except that 60 g of propionic acid was used.

Comparative Example 3
A catalyst was prepared in the same manner as in Example 3 except that 80 g of propionic acid and 200 g of citric acid were used.

Test Example Catalytic Activity Test In the conventional method, the conversion rate of propylene is usually 90% or more, the selectivity for acrolein and acrylic acid is about 85-98%, and the yield of acrolein and acrylic acid is 77- It is reported to be 98%. However, since the performance test conditions of the catalyst are greatly different, it is not meaningful to directly compare the numerical values presented in each prior art document.

  In order to measure the activity of the catalyst produced by the method of the present invention, the produced catalyst is produced into pellets of a certain form and charged into a reactor to carry out an oxidation reaction of propylene, thereby acrolein and acrylic acid. Manufactured. When producing acrolein and acrylic acid, the reaction temperature is 200 to 350 ° C., the reaction pressure is 1 to 3 atm, the propylene is 1 to 10% by volume, the oxygen is 1 to 15% by volume, the water vapor is 5 to 60% by volume, and the inert gas is 20 to 80%. % Of the raw material gas was introduced onto the catalyst at a space velocity of 500 to 5000 hours (STP). The results of reaction experiments for the examples and comparative examples are shown in Table 1. The propylene conversion rate and acrolein yield were calculated by the following formulas 1 to 3.

[Formula 1]
Propylene conversion rate (%) = [(number of moles of reaction propylene / number of moles of propylene supplied)] × 100
[Formula 2]
Acrolein selectivity (%) = [(mol number of produced acrolein / mol number of reacted propylene)] × 100
[Formula 3]
Yield (%) = [(moles of acrolein and acrylic acid formed / (moles of propylene supplied)]] × 100

From the results of Table 1 above, Examples 1 to 5 of the present invention have propylene as compared with Comparative Examples 1 to 3 by preventing drastic decomposition of organic acids and suppressing pore damage by adding a drying control additive. It can be seen that the conversion rate, acrolein selectivity, and the yield of acrolein and acrylic acid are excellent.

Claims (10)

A catalyst for partial oxidation reaction represented by the following chemical formula 1 having a surface area of 15 to 18 m ² / g;
[Chemical formula 1]
_{Mo a Bi b Fe c X d} Y e O f
Where
X is one or more elements selected from the group consisting of Co and Ni,
Y is one or more elements selected from the group consisting of K, Cs and Rb,
a, b, c, d, e and f indicate the atomic ratio of each element,
However, when a is 12, b is 0.5 to 2, c is 0.5 to 2, d is 3 to 8, e is 0.005 to 0.2, and f is an oxidation of each element. It is a numerical value determined by the state. (A) After dissolving an aqueous solution of at least one metal salt selected from the group consisting of molybdenum, bismuth, iron, cobalt, nickel, potassium, cesium and rubidium in an organic acid, a drying control additive is added to the catalyst suspension. Producing a suspension;
(B) vacuum drying and pulverizing the catalyst suspension to produce catalyst powder;
(C) A method for producing a catalyst for partial oxidation reaction of the following chemical formula 1 comprising the step of calcining the catalyst powder in an air atmosphere:
[Chemical formula 1]
_{Mo a Bi b Fe c X d} Y e O f
Where
X is one or more elements selected from the group consisting of Co and Ni,
Y is one or more elements selected from the group consisting of K, Cs and Rb,
a, b, c, d, e and f indicate the atomic ratio of each element,
However, when a is 12, b is 0.5 to 2, c is 0.5 to 2, d is 3 to 8, e is 0.005 to 0.2, and f is an oxidation of each element. It is a numerical value according to the state. The method according to claim 2, wherein the drying control additive is selected from the group consisting of substances having a surface tension lower than that of water and a boiling point higher than that of water. The drying control additive is glycerol, propionic acid, formamide, nitromethane, propyl alcohol, butyl alcohol, ethanediol, nitroethane, amyl acetate, ethyl propionate, ethyl malonate, furfurol, (α, β, γ) -picoline, The production method according to claim 2, wherein at least one selected from the group consisting of piperidine, phenylhydrazine, 1-pentanol, 3-methylbutanol and isovaleric acid is used. The method according to claim 2, wherein the drying control additive is added in an amount of 10 to 60% by weight per 100 parts by weight of the organic acid. The method according to claim 2, wherein the organic acid is an organic acid having 1 to 10 carbon atoms selected from the group consisting of nitric acid, citric acid, maleic acid, and oxalic acid. The production method according to claim 2, wherein the catalyst of Formula 1 is used as a catalyst for partial oxidation reaction of propylene or isobutylene. A method for producing an unsaturated carboxylic acid comprising a step of partially oxidizing an alkane, alkene or a mixture thereof in the presence of a catalyst represented by the following chemical formula 1 produced by the method according to any one of claims 2 to 7.
[Chemical formula 1]
_{Mo a Bi b Fe c X d} Y e O f
(In the above formula,
X is one or more elements selected from the group consisting of Co and Ni; Y is one or more elements selected from the group consisting of K, Cs and Rb; a, b, c, d, e and f represent the atomic ratio of each element; provided that when a is 12, b is 0.5-2, c is 0.5-2, d is 3-8, e is 0.005-0 .2 and f is a numerical value depending on the oxidation state of each element) The manufacturing method according to claim 8, wherein the unsaturated carboxylic acid is acrylic acid or methacrylic acid. A method for producing an unsaturated nitrile comprising a step of partially oxidizing an alkane, alkene or mixture thereof and ammonia in the presence of a catalyst represented by the following chemical formula 1 produced by the method according to any one of claims 2 to 7.
[Chemical formula 1]
_{Mo a Bi b Fe c X d} Y e O f
(In the above formula,
X is one or more elements selected from the group consisting of Co and Ni; Y is one or more elements selected from the group consisting of K, Cs and Rb; a, b, c, d, e and f represent the atomic ratio of each element; provided that when a is 12, b is 0.5-2, c is 0.5-2, d is 3-8, e is 0.005-0 .2 and f is a numerical value depending on the oxidation state of each element)